blender 2.8: where is the "axes" tool for moving vertices visually?
The 3D manipulator widget can be enabled from the toolshelf (left of the 3D viewport) using this "arrows" button:


  




In addition to the "move along X,Y,Z" action, this manipulator also enables the "move on the XY, XZ or YZ plane" (see the little squares between the axes).

There are also other kinds of manipulators in the tool shelf that you can choose from: move, rotate, scale and all the three things combined.